Fluid-energized, or inflatable, packers are isolation devices used in a downhole wellbore to seal the inside of the wellbore or a downhole tubular. They rely on elastomeric bladders to expand and form an annular seal when inflated by fluid pressure. Typically, inflatable packers are controlled by packer valves. Various configurations of packer valves have been devised, including two-valve controlled packers in which one valve is used to inflate the packer and the other is used to regulate the maximum pressure applied to the packer.
However, in the event that the inflatable packer fails, current two-valve controlled packers may be unable to close off the packer fill port. Pressure within the tubular may cause unrestricted fluid flow through the packer fill port into the surrounding annulus. This flow may lead to damage to the downhole tool. In addition, an undesired communication path to the surrounding annulus may remain open.